How can I completely stop my Motorola Android phone from updating OR prompting for updates?

It annoys the HELL out of me how like every 5 minutes there's a message that pops up that says "UPDATE YOUR PHONE UPDATE YOUR PHONE!" and I always say "No thanks, maybe later." and it keeps popping up every 5 minutes. I've TRIED disabling all the apps that have the word "update" or "notifications" in them. Okay so I was like OKAY FINE ILL UPDATE and then I updated the phone. AND IT UPDATED TO THE LATEST VERSION OF KIK WHICH DOESN'T LET YOU USE HASHTAGS TO JOIN GROUPS!!! I got so mad. So now I have no clue how to DEUPDATE it. I don't need updates cuz I don't care if someone hacks one of my phones because of security issues because those are throwaway phones that I literally have 12 of. The point is, updates screw EVERYTHING up and they're annoying as hell because I'm on my phone 24/7 almost and I don't WANT to turn it off for 10 minutes! So I'm asking, is there a way to COMPLETELY DISABLE ALL UPDATES AND ALL NOTIFICATIONS FOR UPDATES EVER?!!! It pisses me off so much. Please help me!